“GOSSIP GIRL” celebrates its 100th episode with the wedding of Blair and Prince Louis (Leighton Meester, Hugo Becker) at 8 p.m. on KTLA.

SERIES

106 & Park: The hip-hop countdown show devotes a special episode to the challenges of teen parenting (6 p.m. BET).

Heat Seekers: This new episode explores the spicier side of San Diego’s food scene (8 p.m. Food).

The Mortified Sessions: “Breaking Bad’s” Bryan Cranston and “Community’s” Danny Pudi share their torturous tales in this new episode (8 p.m. Sundance).The Real Housewives of Beverly Hills: The women reunite to reminisce in Part One of a two-part special (9 p.m. Bravo).RuPaul’s Drag Race: Elvira, Mistress of the Dark, is a special guest judge on the talent competition’s horror-themed season premiere (9 p.m. Logo).Cake Boss: Next Great Baker: The winner is revealed as the culinary competition ends its latest season with an expanded episode (9 p.m. TLC).Bizarre Foods America: New Orleans is the latest destination for host Andrew Zimmern (9 p.m. Travel).